Motor vehicle air suspension system



Feb. 16, 1960 H. -r. szo sTAK ETAL 2,925,284

MOTOR VEHICLE AIR SUSPENSION SYSTEM Filed March 7. 1957 :s Sheets-Sheet2 H.T. "SZ'OSTAK 11% -ggggg 34 8. 6. Wu FIG. 3 BY A? fl I ATTORNEYS Feb.16, 1960 H. T. SZOSTAK EI'AL 2,925,234

MOTOR VEHICLE AIR SUSPENSION SYSTEM Filed March 7. 1957 3 Sheets-Sheet aI ATTORNEYS! FIG. 6

I -iaenti2n rel tes e ra y :tden l e: suspension 2s, .sh aismimhesystem-V V I sweet-2 he pres nt nven ion is oipmvidqan flair sus ect?syst m 02?! nQ QIflehiqle:incorp ratingievelil s. me n m au om i ally mtaining aipied ter aaiass l'r lationshin -btween theehicle-z'chassisiannane m d whe l s a dless o themed ionlthe-ychicleiii-A obiset is-Lto pmviideia v em of thise yne level;- jieg-mseha ism n'which-l he fillmg. an

air springs may be selectively eifected a Qifiegent fair flow :ie 'eailtm vehi le, anthliaiticu arivztoaherleveiconyen'tionallymountedbetweenzthe vehicle trame andga gioiicerafren't suspension membetxnotshown Each' fi n't flevelingiilalve isi'connected bymeans-of2anarm;18*anfl -a :link l-Qxrto an zuppersuspension' arm 21sojthat the :leveling' valve be responsive to changes in therelaiibnshipgbe'tween ztheaveliicleframe and the xoad Wheels.

The rearsleveling: valve 16 is mounted uponaside frame rail 20 of thevehiclechassis and is connected by 7 means of an amt :23 and alink-24Lito1therear axlehousii-11326 to :beuzesponsive ato variations inthe relationship alietvve en lthevehicle frame :and";1he .:1 ear roadwheel's.

V sEach :reai'. air spring 22 is mountedcibetween gthe frame and altrailing arm lipivota'llyconnectepiwit itsiforward V endm the tail 20and atzitssrearwarql 'endi tozthe v mlflht valves :for controlling thehow 20f air :to rand froth exhaustingsofithe ?!'meens of:eontro valvsmanslocated. between 92 iats nit ueeveline or; example, Wham-awehicledoor is open.

' A i n te; Qbieet 9 the i vention is o. p o ide a s n le so i wl valvea apt d t9 YQPIIEQL'JJM nl the till ats but lso t xh u t rate ot eaispring-c. Still ane sx qhieet is to o ide?! cont ol val eias esietcqith. {ye le ymsans of a si n l sm tt v hv. ainps es u e when aahan nteflowra e e ir d- Q he be.

J. ct nd dvas s s a: thi .l i qnt nwill 39:1'95. hands; I

if le a na viw,;pa;. i l aie n ave! i. i a osse ue mila a a T.

.6 bu shewina ap h tm difi e I I R ae no so he d eu nas a d articu a v oEiguge 1, the-reference character l Lindicates,anzaii'comr supplies .airunder' p ressureto supply con'cjl ui'tsl 13,

i ad ing toa pai r of .fitont levelingvalves il l and ia single;

y i11 alve .6

p-f q 1eling al s lt -fl en mlth l nanly "o p and the exhausting of ailTLIIQIP, front aii' glue i ac o -sec iona i w t en. fills-h? ne .v his 1sa sl n val e. and, :remq elyl on: 1

tha airclsprings, butzalsoza acontnol. valvecontrolling the :Jiafe'zofithis ai: flow. These econtrol-valves are ;actuated 'hy :means of ail:pressure supplied through control conaut sm :Theconmo1 cond'uitsl7 aresupplied 'withifair from the air. storageiank 12 Ztnrvough a:solenoidxiutofi.

"valve 2.8 \an'anged -to be energized shy the -vehicle battery 29 whenone of 'a plurality ofswitches 3-1 is closedliach switch 31 11's.assoc'iated; with :a vehicle W100i, :and ma in :fact, be the iexisting:courtesy ilight switch; which menmall); :iunctions :to tum on ;a Blightwhen the 'doorsis opened? It; be :seen thatwhenever a do'oriis opened v1 Y June of th'e :switches, '31 will be closed and fiIBjSOlBIIOid valve2-8; ener'gized to openthe; solenoid valve 'andrpermit an to.'beisuppliecl'through zthecssupply; conduits-21 1mm leveling-valves; r V7 e Rhodes/cling valves, 14;and 16 arersimilar, ands-one of thezfimntvalves.ll wilhbedescribed'in detail.

ZRe'ferring now to Figures "2 to ;5 inclusive, iit twill he seen that eachleveling valve 14 comprises a valve'hous ihg.;32ihavingwan;in1et port33: connected'sto ther airesupply conduitiilfi f rom the storage atank.s'-l"he;aleveling waive also has an outlet port 34' connected toatmosphere, anti a pmgt. 36 adapted. :to be; connectedvto *the:adjacem." aii: spring; a r Thesleveling valvelhousingfiz incorponatesmcomhinecl inlet and 'outlet valve; to-control :the flowrof :aitwtosiheair springgiromythe air :storagetankzand itheaflow of *aii: from the?air :spring. to exhaust; 'valve :disc.;37-.-=ismoi- -v mallwheld upon;-it s seat by. means roi :a :valve spring/38 v reciprocated by nieans ofa connection with a crank pin passageway-36leading toxtheair spring.

passagewayAlextending through'theivalve;plunger. 39.",

; as? o asl it i o cha g an t a e tank. 12, wh ch 4:111ccentrically:arrangedonthe actuatingjhaft 42',wwh'ich in tupn isjconnectedtoiithepend'of thear m-zla; It jwill beiseen-ithat-when the valveplunger'39.:israised airzfrom the.;in1et. port; 33 passes around (the -valvediscf37 tolithe fwhenrthe valve plunger. 39 -isv lowered, its :upper endistspacmiv r m the valve is 37, t s bl he ommunie cation. betw he. airsp n pas ag w y Ma lman-a ia thus connecting passageway 36 to-lthesouteleti portf34 tol enablesainstosbmexhaustecl fromitheispring. ILFWHlbeapparenffro'm the foregoing thatit-hefrota-r tion of the actuating shaft'42, in response to'the changes iii the r 1ationship "between the"vehicle chassis and the a gl acentroad wheel, fa'i'ses vorIijlovvers thevalve plunger 39" to penhit ai to flo.w' fromthe ain sto rage tankgtothe ait' seam j se the ehic e. toits n mal d je'h ig afftfefth loaduponthe vhi ilefhas been increa scj'cl' i 7 l-heut iescnibedsnioredetail later, :each o'f the T llevielingfiizalvesglstrami 16incoiiporates notonly inlet 'and the. vehicle to its normal height afterthe load upon the vehicle has been decreased...

As previously mentioned, the rate of air flow to and from the air springis controlled by, a control valve located between. the inlet and outletvalves of the leveling valve assembly andthe 'airIspring; In theillustrated embodiment of the invention, this control valve is containedwithin the leveling valve housing, but it could be located in theconduit between the leveling valve and the air spring, or adjacent theair spring itself.

As best seen in Figure 3, the valve housing 32 has a control port 44connected to the control conduits 27. Control air supplied to the port44 acts upon a plunger 46 adapted to operate a control valve 47 arrangedin axial alignment with the plunger. When all vehicle doors are closed,the solenoid valve 28 is deenergized and the control conduits 27 are cutofi? from the air storage tank 12, so that the plunger 46 will beinopera-' .control valve which controls the rate of air flow betiveasshown in Figure3. Under these conditions, air

flow to'and from the air spring must pass through a filter element48arranged in the passageway 36 from the leveling valve to the air springport 49 which is connected to the. adjacent air spring by means of aconduit 51. The filter element 48 may be a porous ceramic or sinteredbronze filter which will permit air flow only at a relatively slow rate.Continuous leveling at a slow rate is thus provided to slowly correctany improper car attitude.

When any door is opened, one of the switches 31 will be closed toenergize the solenoid cutoff valve 28 and open the valve to permit airfrom the .air storagetank 12 to flow through the control valve'conduits27 to the control port .44 of the leveling valve assembly. 1 Thiscontrol air acts upon' the head of the plunger'46' to depress the latterand engage the valve stem 52-of the control valve 47 to open the latter.This permits air at a fast rate to flow through passageway 36, controlvalve 47 and passageway 53, thus bypassing the restriction provided bythe filter element 48. Thus, any leveling which is called for by theingress or egress of passengers may be rapidly accomplishedsimultaneously with the load change, and may usually be completed beforethe vehicle doors are all closed. Shouldthe leveling not be completed,or should it be improper for some reason, the leveling may continue at aslow rate through the porous filter element 48 after the doors areclosed.

It will be noted that the single control valve provided for eachleveling valve controls not only the rate of air flow to the air springduring filling operations, but also the flow of air from the air springduring exhausting of the air spring. An open circuit can thus beconveniently used and the air exhausted directly to atmoshere withoutthe necessity of providing a return line and a separate control valve tocontrol the flow of-exhaust arr.

A modification of the control valve is shown in Fig ure 6. Here it willbe noted that flow of air between the air spring port 61 and thepassageway 62 from the leveling valve 63 may be either through arestricted passageway 64, or through a valve 66: The'valve 66 is held inclosed position by a spring 67 when the vehicle doors are all closed sothat the rate of flow to and from the air spring is accomplished at aslow rate through the restrictedpassageway 64. When a door is opened andcontrol air'is supplied to. the control port 68, it acts upon-the head69. of the" valveito lift the latter-from its seatto permit flow of airto and from the air spring at afast rate. i i

In a modification shown in Figure 7, the restriction 64 is replaced by anotch 71 provided'inthe head of the valve 66 to permit a slow air flowpast the valve 66 even when the latter is in its closed position. Ifdesired, the notch could be provided in the valve head.

In the illustrated the valve seat instead of embodiment of theinvention, the

tween each air spring and its leveling valve, is actuated by airpressure under the control of a solenoid cutoff valve. The inventioncontemplates the actuation of the control valve by other means, such aselectrically or mechanically, in response to a signal from a vehicledoor. Likewise, the control valve may be actuated in response to signalsother than vehicle door position, such as in response to a manualcontrol or an automatic control actuated by other vehicle components.

It will be understood that the invention is. not to be limited to theexact construction shown and described, but that various changes andmodifications may be made without departing 'from the spirit and scopeof the invention, as defined in the appended claims.

What is claimed is:

1. In a motor vehicle having a sprung member and an unsprungmember,anair'sp'ring resiliently connecting said members, a source 'of airpressure for said air spring, valve means shiftable between twopositions for controllingthe flow of air between said air source andsaid air spring at two dilferent flow rates, a connection betweensaidair source and said valve means, a solenoid operated valve in saidconnection, and a switch operated bythe opening and closing of a door ofsaid motor vepositions, and a valve actuated in response to the positionof a door of said motor vehicle controlling the connection between saidair source and said air actuated means.

3. In a motor vehicle having a sprung member and an unsprung member, anair spring resiliently connecting said members, a source of air pressurefor said air spring, leveling valve means responsive to variations inthe relationship' between said sprung and unsprung members to controlthe flow of air from saidair source to said air spring and from said airspring to exhaust, control valve means in series with said levelingvalve means to vary the rate of air flow to and from said air spring,means connecting said control valve means to said air source, a cutoffvalve in said connecting means, and means responsive to the opening of adoor of said motor vehicle to actuate said cutoff valve to actuate saidcontrol valve means to effect said flow variation.

1 4. In aymotor vehicle having a chassis member and a'plurality of roadwheel members, an air spring for each of said road wheel members, asource of air pressure, a leveling valve for each of said air springs,each of said leveling valves having connections to said air source, tothe associated air spring and to exhaust and being responsive tovariations in the relationship between said chassis member and theassociated roadwheel member to control the flow of air between saidconnections to admit air into or exhaust air from said air spring,acontrol valve controlling the connection between each of said levelingvalves and its associated air spring, each of said control ,valves beingshiftable between one position restricting the flow of air through saidlast named connection'to aslow rate and a second position opening saidlast named connection to permit a materially faster flow. ratetherethrough, a connectionbetween said, air source and each of saidcontrol valves, a solenoid controlled valve controlling said lastmentioned connections,

anda

considerably fas j membeiito maintain afpredeterminedrelationship there?between, said leveling control'iimechanismihaving a'passagecommunicating with said: air spring, ga'valve. controlling said passage,said valvchaving a headprovidedl; with a restrictedopeningitherethroughfio permitacon- 't-inuous slow flow of airbetweensaid leveling icontrol 5. In a motor vehicle having a chassis-member anda road wheel member, an air spring between said members, a source of airpressure, a leveling valve, saidleveling valve having connections tosaid air source, to said spring and to exhaust and being responsive tovariations in the relationship between said chassis member and saidtion'between said leveling valve-iandsaida air spring, said controlvalve being shiftableibetween' one position nection to a slow rate and asecond position opening flow rate therethrough, a connection betweensaid air source and said control valve, a valve controlling said lastmentioned connection, and means responsive to the I opening of avvehicle door to actuate said last named valve to shift said controlvalve to said: second position from'saidfainspring during the exhaustoperation.

, '9. Inamotor vehicle having" a chassis member and a.

permitting a, relatively fast filling or exhau'stingof said air springwhen a vehicle door-is open.

V restricting the flow of air through said last named .con- V said lastnamed connectionto permit a materially faster an air spring, a source ofone of said members, actuating means for said leveling control mechanismoperatively connected to the other'of said members to be responsive tovariations in the relationship between said chassis member and saidwheel member to maintain a predetermined relationship therebetween,means establishing communication between said leveling control mechanismand said *air springand havingfa constantly open restricted orificetherein, abypass passageway in said means bypassing said restrictedorifice to permit air flow between said leveling control mech-v anismand said air spring in both directions at a faster 1 rate than permittedby-said orifice alone, a valve normally'closing said bypass passageway,an air connection from said air source to said valve, andmeans'controlling said connection to admit air from said air source tosaid valve to open said valveand' said bypass passageway to [increasethe rate of airflowto said air spring during 6. In a motor vehiclehaving a" chassis member re elementfp 71 5 p 7. Ina motorvehicle'having'a chassis member -r control mechanism operatively;cbnnected"to 'the-oth of said members'to be ;respons v to .vana'tions inTthe inber nd sa d wheel relationship between said {chassis mechanismand said air spring when lsaidvalve is close'd;

and actuating meansforfsaid valve to openztha lattg s' and permit aconsiderablyfaster show of: air throughisaid passageway.

8. In a motor vehicle ha -siliently supported [upona wheel memberby,-means of an-airgspring, and; asource of ,airj under pressure forcharnb the -fill operation andj'to, increase the rate of air flow.

said 'merrib ers,-v a source of air pressure, a levelin'gvalveresponsive'to variations in the relationshipfbe'tween said .cliajssismember andrsaidfroad, wheelimember and having onnections-,to -saicl-airsource andito .e rhaust a, pair' of er, and f a control valve'jasisociated ehiclefto Zpermit air fiowjto'and References cad infthefileiofthispatent I "U EDIS T S A N Sf 1,666,748: Apr. 17,. 1 92 8.2,787,475 I Apr. 2, 19 57 Bertsch Aug. 19,

7 air under pressureffor said air spring, leveling control mechanismmounted upon,

I ithisaid last amed-connection to selectivelyadmit air from said source7 o said air chamber to act upon said actuating member,

andrnove s'aid shii'tofi valvejto' open position to perniit ti air flovvthrough said 'otheripassageway as well as through (said-restricted vpassa'g eway to ,or from said air spring at raster rate whenever saidleveling valveis actuated I valve fin' response to the opening of a"door o f'jsaid froin' said air f

